London's stalwart pirate radio underground has been an essential tool for the growth of electronic dance music since the mid-80's, specifically Acid House, Breakbeat Hardcore, Jungle/Drum'n'Bass, Ragga and now Grime/Dubstep. It provides, free of charge to the listening public, a wealth of brand new music, often produced right in their own neighborhoods, that mainstream radio either can't or won't play (although that's changed greatly in recent years), as well as offering a community rallying point culturally. There are a few perspectives of pirate radio, one from The Powers That Be concerning "theft" of the airwaves and another that's more about the music. Here's a local news item from the early 90's with the "official" message:

Another London news clip, this one from 1994, the early days of Jungle, with squareness in full effect:

There's a sense of mystery surrounding pirate radio that lies in its clandestine nature - both musically as well as physically. Jungle and Ragga both got very little attention from the mainstream during their inception periods but flourished through the pirates via dedicated DJ's and promoters, some of whom turned their popularity into lasting careers in radio, with a few stations actually going legit. Throughout the "Second Summer of Love", as the heady Acid House-drenched summer of 1988 is often called, pirate radio was the beacon in the night, guiding clubland refugees to the nonstop party. This UK documentary from '94 shows a bit more of a balanced viewpoint, particularly showing the establishment's skewered views in stark light. Check the intro for a track that tweaks a sample from the news clip above!

Part One:

Part Two:

Here's another documentary from 1996 that heavily features Kool FM, one of Jungle's most popular pirates, still on the air to this day! Lots of killer shots with leading figures from the scene like DJ Brockie and DJ Ron:

Part One:

Part Two:

Part Three:

There's well over an hour's worth of video up there, so kick back and take it in at your leisure. If you're still interested in the pirates, you can check out this regularly updated list of all the pirates in London, and then use this scanner to actually listen to them!